Map of the column density of C¹⁸O(1− 0). The black stars and triangles present the locations of protostellar and prestellar cores, respectively. The coordinates of the protostellar and prestellar cores were taken from Könyves et al. (2015). The black circle marks the location of the W 40 H II region (radius ∽ 3′) and the black filled circle in the bottom-right corner illustrates the beam size of 60′′. The clippinglevel for the ¹³CO and C¹⁸O data corresponds to a signal-to-noise ratio greater than five. Gaussian fitting to each pixel was done.